PP period

I had my son January 7, 2020 and breastfed until November, had my first period in December, was due for it to start again almost 3 days ago and still haven’t had it or any signs of it. Is it normal for it be wacky still or should I take a pregnancy test? I don’t really have any pregnancy symptoms besides occasional nausea but I’ve had that since last weekend when I had a vertigo episode. Any advice welcome!!